SigmaHQ/rules/windows/process_creation/win_workflow_compiler.yml

title: Microsoft Workflow Compiler
id: 419dbf2b-8a9b-4bea-bf99-7544b050ec8d
status: experimental
description: Detects invocation of Microsoft Workflow Compiler, which may permit the execution of arbitrary unsigned code.
tags:
    - attack.defense_evasion
    - attack.execution
    - attack.t1127
author: Nik Seetharaman
date: 2019/01/16
references:
    - https://posts.specterops.io/arbitrary-unsigned-code-execution-vector-in-microsoft-workflow-compiler-exe-3d9294bc5efb
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image: '*\Microsoft.Workflow.Compiler.exe'
    condition: selection
fields:
    - CommandLine
    - ParentCommandLine
falsepositives:
    - Legitimate MWC use (unlikely in modern enterprise environments)
level: high
Converted Sysmon/1 and Security/4688 to generic process creation rules 2019-01-16 22:36:31 +00:00			`title: Microsoft Workflow Compiler`
Added UUIDs to rules 2019-11-12 22:12:27 +00:00			`id: 419dbf2b-8a9b-4bea-bf99-7544b050ec8d`
Converted Sysmon/1 and Security/4688 to generic process creation rules 2019-01-16 22:36:31 +00:00			`status: experimental`
			`description: Detects invocation of Microsoft Workflow Compiler, which may permit the execution of arbitrary unsigned code.`
			`tags:`
Increased indentation to 4 * Converted (to generic sigma) rules * Converter outputs by default with indentation 4 2019-03-01 23:14:20 +00:00			`- attack.defense_evasion`
			`- attack.execution`
Added missing tags and some minor improvements 2019-03-05 22:25:49 +00:00			`- attack.t1127`
Converted Sysmon/1 and Security/4688 to generic process creation rules 2019-01-16 22:36:31 +00:00			`author: Nik Seetharaman`
fix: fixed missing date fields in remaining files 2020-01-30 15:07:37 +00:00			`date: 2019/01/16`
Converted Sysmon/1 and Security/4688 to generic process creation rules 2019-01-16 22:36:31 +00:00			`references:`
Increased indentation to 4 * Converted (to generic sigma) rules * Converter outputs by default with indentation 4 2019-03-01 23:14:20 +00:00			`- https://posts.specterops.io/arbitrary-unsigned-code-execution-vector-in-microsoft-workflow-compiler-exe-3d9294bc5efb`
Converted Sysmon/1 and Security/4688 to generic process creation rules 2019-01-16 22:36:31 +00:00			`logsource:`
Increased indentation to 4 * Converted (to generic sigma) rules * Converter outputs by default with indentation 4 2019-03-01 23:14:20 +00:00			`category: process_creation`
			`product: windows`
Converted Sysmon/1 and Security/4688 to generic process creation rules 2019-01-16 22:36:31 +00:00			`detection:`
Increased indentation to 4 * Converted (to generic sigma) rules * Converter outputs by default with indentation 4 2019-03-01 23:14:20 +00:00			`selection:`
			`Image: '*\Microsoft.Workflow.Compiler.exe'`
			`condition: selection`
Converted Sysmon/1 and Security/4688 to generic process creation rules 2019-01-16 22:36:31 +00:00			`fields:`
Increased indentation to 4 * Converted (to generic sigma) rules * Converter outputs by default with indentation 4 2019-03-01 23:14:20 +00:00			`- CommandLine`
			`- ParentCommandLine`
Converted Sysmon/1 and Security/4688 to generic process creation rules 2019-01-16 22:36:31 +00:00			`falsepositives:`
Increased indentation to 4 * Converted (to generic sigma) rules * Converter outputs by default with indentation 4 2019-03-01 23:14:20 +00:00			`- Legitimate MWC use (unlikely in modern enterprise environments)`
Converted Sysmon/1 and Security/4688 to generic process creation rules 2019-01-16 22:36:31 +00:00			`level: high`